Panasonic Corporation

Christian Pennec

Herb Evans

A power tuning method determines values of a magnitude control signal that controls the magnitude of an amplitude-modulated power supply signal applied to a power supply port of a power amplifier of a polar transmitter and an amplitude control signal that controls the amplitude of a constant-envelope phase-modulated signal applied to a radio frequency input port of the power amplifier necessary to set the output power of the polar transmitter to a target output power. The method is repeated and performed for a plurality of different target output powers. Output-power-level dependent power control parameters calculated from the applied method are used to set the values of the magnitude control and amplitude control signals during normal operation. Using the output-power-level dependent power control parameters, the magnitude control and amplitude control signals are changed in a continuous manner with changes in output power and over the full dynamic range of output powers the polar transmitter can be commanded to operate, thereby obviating any need for a closed-loop power detection mechanism to correct for power discontinuities.

Methods for tuning and controlling output power in polar transmitters

Methods and apparatus for dynamically compensating for signal variations in communications transmitters employing switch-mode PAs. An exemplary method includes first identifying a predetermined signal characteristic in an input signal applied to an input of a switch-mode PA. A modulated signal produced at the output of the switch-mode PA containing the identified signal characteristic is then sampled at approximately the same time the identified signal characteristic appears at the output of the switch-mode PA, to generate a digital sample representing an actual value of the identified signal characteristic. An error signal representing the extent to which the actual value deviates from an expected value is then generated. Finally, the DC level and/or gain of the input signal to the switch-mode PA is modified to reduce the error. By reducing the error in this manner, signal variations that adversely affect the accuracy of the switch-mode PA output signal are dynamically compensated for.

Methods and apparatus for dynamically compensating for DC offset drift and other PVT-related signal variations in polar transmitters

An amplification circuit and scaling method are configured to apply optimum biasing characteristics such that a multistage power amplifier operates according to defined performance characteristics. The operating conditions of the multistage amplifier are optimized by applying independent bias voltages to each stage within the multistage amplifier while operating in a maximum power output range. To achieve optimum or near-optimum operating conditions, each bias voltage is independently scaled according to a specific power output level.

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Cupertino, CA, United States of America

Christian Pennec